Shuddering under acceleration

[dannyca13]

I need some help. I've just completed a redtop swap into my s13. While test driving it i noticed a shudder that seems to be coming from the rear end while accelerating in 1st and 2nd at low rpm. I'm not sure if its wheel hop, tranny related or a boost leak. I'd appreciate any insight in how to diagnose/correct this problem.

On a funnier note my stock muffler decided to hop off my car last night. It said to hell with this and bailed after some loud scraping. I figure its the best way of saying buy a new exhaust.

[idlafie]

Check your rear subframe bushings. They may be worn. All that power you are putting down is only worsening the problem. You can alleviate the problem by compressing the subframe bushings with the following:
http://www.specialtyz.com/subspacers.htm
Install instructions are on this page: http://www.capitalzoftexas.com/techtips/
Don't let the 300ZX info on the page fool you....240SX's have the same setup and follow the same install procedure.
Anyhow hope this helps.
ID

[dannyca13]

Just an update i fixed the problem in case anyone else has a similar problem. One of the driveshaft bolts near the tranny end fell out. So i sourced one from the junkyard and now the shuddering is gone. Driveshaft balance seems to be extremely important.

[transient]

Even more-so at high speeds as well... I'm really surprised you only felt it at 1st - 2nd gear speeds